Audio amplitude wrapping is a form of clipping distortion where the most significant bits have been lost but the least significant bits are still valid, analogous to numerical overflow in computational integer arithmetic. Visually this may look as if the signal wraps from one side of full scale the other.
Audio wrapping generally occurs when audio is converted to an integer incorrectly. There are two likely candidates to produce this phenomenon: one is that the firmware of some analogue to digital hard disk recorders exhibits this wrapping behaviour; the other candidate is poorly written audio processing software. Amplitude unwrapping shares some similarities with phase unwrapping, but there are two significant differences which may be exploited by the method described in the following specification. The solution presented herein is to find an unwrapping that minimises the total cost of a filtered version of the unwrapped signal.
Thus, the phenomenon of wrapping is generally an undesirable alternative to the signal being clipped at the extrema. Thus, the degree of wrapping is the number of times by which the representable range has been exceeded. The number of times can be a signed integer. That is, where the degree of wrapping is a negative numbers, the range has been exceeded from below, and a positive degree of wrapping defines wrapping over the maximum value (or ‘overflowing’). The magnitude of the wrapping value defines a number of times the signal has wrapped.